Method of and apparatus for delivering sand into molds



' July 17, 1928-. 1, 71,726

0. NAGEL ET AL" METHOD 6? AND mum FOR nzmvanme Sm nrro HOLDS Fiied April 18, 1927 0 -7 Na-gzl w hilm Mumps NVENTORfi Patented. July 17, 192s.

UNITED STATES PATENT OFFICE.

o'rro NAGEL AND WILHELM kmmrrnn, or-nunnacfi. IBADEN, GERMANY, ASSIGNORS T0 nanrscnn masonmnnmnmx & msnnemssnnnr vonmms o. snnonn um: snnonn & mum, on nunmcn, IBADEN, 033mm.

METHOD OF AND APPARATUS FOR DELIVERING SAND INTO HOLDS.

Application filed April 18, 1927, Serial No. 184,823, and in Germany March 28, 1927.

Our invention relates to a method of and apparatus for delivering sand to molds by means of compressed air, and effecting the desired compacting of the sand in the mold.

Previous efforts along this line have been unsuccessful or unsatisfactory. The compacting requires the delivery of the sand at comparatively highw'elocity, but we have discovered that the difiiculty encountered has been due to the failure to separate the stream of high velocity compressed air. from the sand before the latter enters the mold. This air, when mixed with the sand in the mold, acts as a cushion to prevent compacting of-the sand, and the high velocity compressed air separating from the sand in the mold entrains substantial quantities of the sand and carries' it out of the mold. The sand remaining in the mold is loose, instead of being compacted to the desired density.

We have succeeded in overcoming this difficulty by a novel construction of nozzle whereby the separated particles of sand in the rapidly moving stream are brought into closely juxtaposed position, comparatively free of air, the cross-section of the stream of sand is reduced, and the compressed air is permitted to expand and escape. Thus, a solid jet of sand, comparatively free of compressed or high velocity air, is projected into the mold where it acts to compact the previously delivered ,sand and remains substantially where it is delivered.

Various devices suitable for carrying-out our improved method are illustrated in the accompanying drawing.

In the drawing Fig. 1 is a longitudinal section through the front end of a nozzle according to our invention,

Fig. 2 a cross-section along .line 22 of 'Fig. 1,

Fig. 3 is a longitudinal section through a .modification of the nozzle,

Fig. 4 is a plan of the nozzle according to Fig. 3,

Fig. 5 is a cross-section along line 5-5 of Fig. 3, viewed in the direction of the arrows,

Fig. 6 is a longitudinal section through a. nozzle (pith interchangeable and adjustable tip, an

Fig 7 is a cross-section along line 7.-7 of the Flg- 6.

, or concentrated state.

Like parts are indicated by like numerals of reference in all the figures of the draw- H10.

in carrying out our improved method a jet or stream composed of sand andcompressed air is' propelled by a suitable compressed air or pneumatic conveyor of known veyed to the nozzle 1 through a suitable,. preferably circular pipe by means of the propelling or blowing device in the usual manner. When the jet reaches the nozzle 1 it has'attained its highest velocity and is then deflected from its previous path by the curvature of the nozzle 1. Simultaneously a deformation of the jet takes place due to the rectangular cross-section of the nozzle 1, whereby, as indicated in Fig. 2, the sand stream 2 issues from the mouth of the nozzle 1 in the shape of a flat broad comparatively solid jet separated from the compressed air which merely serves to convey it to the nozzle at the desired velocity, and in a compressed The curved side of the nozzle forms a wall along which the sand particles are brought into closely juxtaposed positions, leaving the air at the other side of the nozzle free to escape without carrying with it any substantial amount of the sand.

Referring to the modification of the nozzle illustrated in Figs. 3 to 5, it will be observed that the nozzle 1 of circular cross-section at 3 is designed at its tip 4 as a fiat broad 1nverted chute or gutter, so that here also the sand to be conveyed issues from the nozzle 1 in the form of .a rectangular broad jet 2.in a concentrated state.

In this form the terminal portion of the nozzle for substantially the full length of the wall which projects at an angle into the path of the'sand stream, has a lateral opening from which the expanding air may egcape before the solid sand stream leaves the end of the nozzle.

The bent nozzle may, as illustrated in Figs. 6 and 7, also consist of two detachable hinged parts 5 and 6, of which part 5 is preferably of circular cross-section, while the part .6 hinged at 7 is designed as a flat broad inverted chute or trough, as in Figures 3 to 5, to attain the end in view.

Various changes and modifications may be made in the details without departing from the spirit of our invention and we desire, therefore, that only such limitations be placed thereon as are imposed by the prior art.

We claim as our invention 1. A nozzle for a pneumatic conveyor for granular materials provided with a tip formed as a broad chute open at the bottom.

2. A nozzle for a pneumatic conveyor for granular materials provided with an adjustable and detachable tip of rectangular cross-section open along one side.

3. In a nozzle for a pneumatic conveyor for granular materials, in combination, a main part of circular cross-section, a curved inverted fiat chute, and ahinge for joining said main part and said chute.

4. A nozzle for delivering sand into molds by compressed air, comprising a cylindrical portion for delivering the sand and compressed air, and a terminal discharge portion of angular cross-section, adapted to bring the same to more compact form, said terminal discharge portion having a wall extending in a direction at an angle to the axis of the cylindrical portion and in the path of movement of the sand,

5. A nozzle for deliveringsand to molds by means of compressed air, and compacting the sand in the mold, which includes a cylindrical portion for delivering the sand and compressed air at high velocity, and a terminal portion having a wall extending in a direction at an angle to the axis of the cylindrical portion and Wider than the diameter of said portion and in the path of move ment' of-the sand, for bringing the sand stream into more nearly solid form, said terminal portion being open along one 'side for substantially the full length of said wall, whereby the high pressure air may escape from the sand as the stream of the latter is changed in cross-section and. before the sand leaves th end of the nozzle.

6. The method of conveying sand to a mold by means of compressed-air, which consists in delivering the sand by means of a high velocity stream of air, and before the sand enters the mold compacting the stream of sand and simultaneously permitting the escape of the high pressure air therefrom,

whereby the sand alone unmixed with the high pressure air is delivered at high velocity to the mold.

7. The method of conveying sand to a mold by means of compressed air, which consists in advancing the sand in a given path by means of a high-velocity stream of air, gradually deflecting the stream of sand from said path and before the sand enters the mold changing the shape of the stream of sand to compact the same and simultaneously permit the escape of air therefrom, whereby the sand alone unmixed with the high pressure air is delivered at high velocity to the mold.-

In testimony whereof We affix our signatures.

OTTO NAGEL. WILHELM KAEMPFER. 

